(49) باب الأَمْرِ بِالصَّلاَةِ عَلَى النَّبِيِّ صلى الله عليه وسلم
It was narrated that Abu Mas'ud Al-Ansari siad:
"The Messenger of Allah (ﷺ) came to us in the Majlis of Sa'd bin 'Ubadah and Bashir bin Sa'd said to him: 'Allah has commanded us to send Salah upon you, O Messenger of Allah; so how should we send salah upon you?' The Messenger of Allah (ﷺ) remained silent until we wished that he had not asked him. Then he said: 'Say: 'Alahumma salli 'ala Muhammad wa 'ala ali Muhammad, kama sallaita 'ala Ibrahima wa barik 'ala Muhammad kama barakta 'ala ali Ibrahim fil-'alamin, innaka hamidun majid (O Allah, send salah upon Muhammad and upon the family of Muhammad, as You sent salah upon the family of Ibrahim, and send blessings upon Muhammad and upon the family of Muhammad as You sent blessings upon the family of Ibrahim among the nations. You are indeed Worthy of praise, Full of glory.)" And the salam is as you know.'"
Reference: Sunan an-Nasa'i 1285
In-book reference: Book 13, Hadith 107
English translation: Vol. 2, Book 13, Hadith 1286